Outdoor advertising installations of the type described above have hitherto only been known in the form of neon high voltage installations (single letters, continuous writing, individual signs, in which the lamp had the shape of the luminous element), in which the outermost plate was back printed grey so that it appeared darker by daylight and appeared brighter by night due to artificial light acting from the back. The overall impression is unsatisfactory because the colors white and black cannot be achieved and bright/dark reversal from day to night does not succeed.
It has surprisingly been found that outdoor advertising installations of the type defined above may be produced by covering the areas of the information plate which appear bright by daylight with a bright back printing and behind that with a dark back printing and covering areas of the information plate which appear dark by daylight with regular pattern of dark lines or dark points. The points and lines can be of any shape, preferably regular shape. Circular points are preferred.
The lines and points may be colored, e.g. dark and bright blue but they are preferably black and white.
Other preferred embodiments are the following: An additional bright or white back printing is applied to the dark printing with removal of that part of the area which has been covered with regular pattern of lines and points.
The points or lines have a covering of 20 to 90%, preferably of 40 to 80%. In consequence, the interspace between the lines or points has a covering of from 10 to 80%, preferably of from 20 to 60%. The information plate is arranged at a distance of 1 to 100 mm in front of the scattering plate.
Further, one or some or all of the back printings are duplicated or multiplicated, and there are two or more information plates and a corresponding number of scattering plates.
The information plates contain additional items of information which have the same apparent brightness and color both by day and by night.
The additional back printing in bright or white ensures by its reflection combined with the effect of the scattering plate, which is preferably a translucent glass plate, that the quantity of light will be better utilized. The preferred distance between the scattering plate and the information plate also contributes to this effect.
The construction of the illuminated advertising installation as a box with neon lamps, scattering plate and information plate is in accordance with conventional practice. The material used for the scattering plate and the information plate is glass or artificial glass, for example of polymethyl methacrylate or polycarbonate. Very fast pigmented printing inks are preferably used for the printing.
Outdoor advertising installations according to the invention having more than one information plate and the corresponding number of scattering plates may carry different items of information on the various information plates and may be constructed, for example, in the form of rectangular prisms with a front and back surface or as cubes with four information plates, and they may be rotatable.
If the information plates in addition have areas which appear to have the same degree of brightness and the same color by day and by night, these areas of the information plate are produced in known manner by simple back printing in the required colour and brightness.